Package it.unimi.dsi.fastutil.longs

Class LongArraySet

java.lang.Object

java.util.AbstractCollection<Long>

it.unimi.dsi.fastutil.longs.AbstractLongCollection

it.unimi.dsi.fastutil.longs.AbstractLongSet

it.unimi.dsi.fastutil.longs.LongArraySet

All Implemented Interfaces:

LongCollection, LongIterable, LongSet, Serializable, Cloneable, Iterable<Long>, Collection<Long>, Set<Long>

public class LongArraySet
extends AbstractLongSet
implements Serializable, Cloneable

A simple, brute-force implementation of a set based on a backing array.

The main purpose of this implementation is that of wrapping cleanly the brute-force approach to the storage of a very small number of items: just put them into an array and scan linearly to find an item.

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
LongArraySet()	Creates a new empty array set.
LongArraySet(int capacity)	Creates a new empty array set of given initial capacity.
LongArraySet(long[] a)	Creates a new array set using the given backing array.
LongArraySet(long[] a, int size)	Creates a new array set using the given backing array and the given number of elements of the array.
LongArraySet(LongCollection c)	Creates a new array set copying the contents of a given collection.
LongArraySet(LongSet c)	Creates a new array set copying the contents of a given collection.
LongArraySet(Collection<? extends Long> c)	Creates a new array set copying the contents of a given set.
LongArraySet(Set<? extends Long> c)	Creates a new array set copying the contents of a given set.

Method Summary

Modifier and Type	Method	Description
boolean	add(long k)	Ensures that this collection contains the specified element (optional operation).
void	clear()
LongArraySet	clone()	Returns a deep copy of this set.
boolean	contains(long k)	Returns true if this collection contains the specified element.
boolean	isEmpty()
LongIterator	iterator()	Returns a type-specific iterator on the elements of this collection.
static LongArraySet	of()	Creates a new empty array set.
static LongArraySet	of(long e)	Creates a new array set using the element given.
static LongArraySet	of(long... a)	Creates a new array set using an array of elements.
static LongArraySet	ofUnchecked()	Creates a new empty array set.
static LongArraySet	ofUnchecked(long... a)	Creates a new array set using an array of elements.
boolean	remove(long k)	Removes an element from this set.
int	size()
LongSpliterator	spliterator()	Returns a type-specific spliterator on the elements of this set.
long[]	toArray(long[] a)	Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array.
long[]	toLongArray()	Returns a primitive type array containing the items of this collection.

Methods inherited from class it.unimi.dsi.fastutil.longs.AbstractLongSet

equals, hashCode, rem

Methods inherited from class it.unimi.dsi.fastutil.longs.AbstractLongCollection

add, addAll, addAll, contains, containsAll, containsAll, forEach, remove, removeAll, removeAll, removeIf, retainAll, retainAll, toLongArray, toString

Methods inherited from class java.util.AbstractCollection

toArray, toArray

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

toArray

Methods inherited from interface it.unimi.dsi.fastutil.longs.LongCollection

addAll, containsAll, longIterator, longParallelStream, longSpliterator, longStream, parallelStream, removeAll, removeIf, removeIf, removeIf, retainAll, stream, toLongArray

Methods inherited from interface it.unimi.dsi.fastutil.longs.LongIterable

forEach, forEach, forEach

Methods inherited from interface it.unimi.dsi.fastutil.longs.LongSet

add, contains, remove

Methods inherited from interface java.util.Set

addAll, containsAll, removeAll, retainAll, toArray, toArray

Constructor Details

LongArraySet

public LongArraySet(long[] a)

Creates a new array set using the given backing array. The resulting set will have as many elements as the array.

It is the responsibility of the caller to ensure that the elements of a are distinct.

Parameters:

a - the backing array.

LongArraySet

public LongArraySet()

Creates a new empty array set.

LongArraySet

public LongArraySet(int capacity)

Creates a new empty array set of given initial capacity.

Parameters:

capacity - the initial capacity.

LongArraySet

public LongArraySet(LongCollection c)

Creates a new array set copying the contents of a given collection.

Parameters:

c - a collection.

LongArraySet

public LongArraySet(Collection<? extends Long> c)

Creates a new array set copying the contents of a given set.

Parameters:

c - a collection.

LongArraySet

public LongArraySet(LongSet c)

Creates a new array set copying the contents of a given collection.

Parameters:

c - a collection.

LongArraySet

public LongArraySet(Set<? extends Long> c)

Creates a new array set copying the contents of a given set.

Parameters:

c - a collection.

LongArraySet

public LongArraySet(long[] a,
 int size)

Creates a new array set using the given backing array and the given number of elements of the array.

It is the responsibility of the caller to ensure that the first size elements of a are distinct.

Parameters:

a - the backing array.

size - the number of valid elements in a.

Method Details

of

public static LongArraySet of()

Creates a new empty array set.

Returns:

a new empty array set.

of

public static LongArraySet of(long e)

Creates a new array set using the element given.

Parameters:

e - the element that the returned set will contain.

Returns:

a new array set containing e.

of

public static LongArraySet of(long... a)

Creates a new array set using an array of elements.

Unlike the array accepting constructors, this method will throw if duplicate elements are encountered. This adds a non-trivial validation burden. Use ofUnchecked() if you know your input has no duplicates, which will skip this validation.

Parameters:

a - the backing array of the returned array set.

Returns:

a new array set containing the elements in a.

Throws:

IllegalArgumentException - if there were duplicate entries.

ofUnchecked

public static LongArraySet ofUnchecked()

Creates a new empty array set.

Returns:

a new empty array set.

ofUnchecked

public static LongArraySet ofUnchecked(long... a)

Creates a new array set using an array of elements.

It is the responsibility of the caller to ensure that the elements of a are distinct.

Parameters:

a - the backing array of the returned array set.

Returns:

a new array set containing the elements in a.

iterator

public LongIterator iterator()

Description copied from interface: LongCollection

Returns a type-specific iterator on the elements of this collection.

Specified by:

iterator in interface Collection<Long>

Specified by:

iterator in interface Iterable<Long>

Specified by:

iterator in interface LongCollection

Specified by:

iterator in interface LongIterable

Specified by:

iterator in interface LongSet

Specified by:

iterator in interface Set<Long>

Specified by:

iterator in class AbstractLongSet

Returns:

a type-specific iterator on the elements of this collection.

See Also:

• Iterable.iterator()

spliterator

public LongSpliterator spliterator()

Returns a type-specific spliterator on the elements of this set.

Set spliterators must report at least Spliterator.DISTINCT.

See Set.spliterator() for more documentation on the requirements of the returned spliterator.

In addition to the usual trait of DISTINCT for sets, the returned spliterator will also report the trait ORDERED.

The returned spliterator is late-binding; it will track structural changes after the current item, up until the first trySplit(), at which point the maximum index will be fixed.
Structural changes before the current item or after the first trySplit() will result in unspecified behavior.

Specified by:

spliterator in interface Collection<Long>

Specified by:

spliterator in interface Iterable<Long>

Specified by:

spliterator in interface LongCollection

Specified by:

spliterator in interface LongIterable

Specified by:

spliterator in interface LongSet

Specified by:

spliterator in interface Set<Long>

Returns:

a type-specific spliterator on the elements of this collection.

contains

public boolean contains(long k)

Description copied from class: AbstractLongCollection

Returns true if this collection contains the specified element.

Specified by:

contains in interface LongCollection

Overrides:

contains in class AbstractLongCollection

See Also:

• Collection.contains(Object)

size

public int size()

Specified by:

size in interface Collection<Long>

Specified by:

size in interface Set<Long>

Specified by:

size in class AbstractCollection<Long>

remove

public boolean remove(long k)

Description copied from class: AbstractLongSet

Removes an element from this set. Delegates to the type-specific rem() method implemented by type-specific abstract Collection superclass.

Specified by:

remove in interface LongSet

Overrides:

remove in class AbstractLongSet

See Also:

• Collection.remove(Object)

add

public boolean add(long k)

Description copied from class: AbstractLongCollection

Ensures that this collection contains the specified element (optional operation).

Specified by:

add in interface LongCollection

Overrides:

add in class AbstractLongCollection

See Also:

• Collection.add(Object)

clear

public void clear()

Specified by:

clear in interface Collection<Long>

Specified by:

clear in interface Set<Long>

Overrides:

clear in class AbstractCollection<Long>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Collection<Long>

Specified by:

isEmpty in interface Set<Long>

Overrides:

isEmpty in class AbstractCollection<Long>

toLongArray

public long[] toLongArray()

Description copied from interface: LongCollection

Returns a primitive type array containing the items of this collection.

Specified by:

toLongArray in interface LongCollection

Overrides:

toLongArray in class AbstractLongCollection

Returns:

a primitive type array containing the items of this collection.

See Also:

• Collection.toArray()

toArray

public long[] toArray(long[] a)

Description copied from interface: LongCollection

Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array.

Note that, contrarily to Collection.toArray(Object[]), this methods just writes all elements of this collection: no special value will be added after the last one.

Specified by:

toArray in interface LongCollection

Overrides:

toArray in class AbstractLongCollection

Parameters:

a - if this array is big enough, it will be used to store this collection.

Returns:

a primitive type array containing the items of this collection.

See Also:

• Collection.toArray(Object[])

clone

public LongArraySet clone()

Returns a deep copy of this set.

This method performs a deep copy of this array set; the data stored in the set, however, is not cloned. Note that this makes a difference only for object keys.

Returns:

a deep copy of this set.